<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>CSS3之3D</title>
<style>
	#main{ width:150px; height:150px; border:1px black solid; 
		perspective:50px; }
	#box{ width:50px; height:50px; background:red; 
		color:white; margin:50px; transition:1s; }
	#main:hover #box{ transform:rotateY(180deg);}
</style>
</head>
<body>
<div id="main">
	<div id="box">CSS3</div>
</div>
</body>
</html>
